1. Field of the Invention
This invention relates to an apparatus for de-nesting, or separating, containers having flanged edges, and in particular, to apparatus for separating individual flanged containers from a stacked array of nested containers.
2. Background of the Invention
In the fast-food preparation industry it is common practice to package fully prepared comestible articles, such as sandwiches or the like, in clear containers fabricated of a transparent plastic or other suitable material. Such containers are usually provided with a receptacle portion which receives the prepared comestible article. Usually these containers are provided with flanged edges, or lips, which protrude outwardly beyond the basic dimension of the receptacle to receive a covering flap which seals and maintains the attractiveness and freshness of the comestible article.
The flanged containers are commonly fabricated from a sheet of suitable flexible and transparent material by extruding containers from the sheet or by punching the sheet over an appropriate die. The containers are stacked for transportation and are then shipped to the fast-food packager, usually in a nested configuration. By a nested configuration it is meant that the exterior of the receptacle portion of each container is received within the receptacle of the next-lower container. U.S. Pat. No. 2,852,157 (Frater), at FIG. 2 thereof, illustrates a side view of a plurality of flanged containers disposed in a nested configuration.
At the fast-food packaging location, it is therefore necessary to separate, or de-nest, the individual flanged containers from the nested stack. Such a de-nesting process is usually done manually as but one step in a fast-food packaging production line. Alternatively, it is known in the art to separate a stack of nested containers by periodically attaching suitable gripping members to the lowermost container and pulling that lowermost container downwardly and away from the stack. The flanged containers nested above the lowermost container are retained in place by suitable flange retainers, or inwardly directed pins. These retainers continue to suppot the remainder of the nested stack of containers by providing support beneath the flanges of the next-lowermost container in the stack as the lowermost container is pulled away therefrom.
However, this downwardly pulling motion imposed upon the lowermost container in a stack subjects the receptacle portion of that lowermost container to a possibly damaging gripping attachment likely to result in perforation or tearing. Further, the downwardly directed force imposed on the lowermost container must be sufficient to pull the flanges thereof over the inwardly directed pins, possibly subjecting those flanges to tearing or rupture. Such damage to the container is, of course, disadvantageous, since it endangers the wholesomeness and saleability of a fully packaged comestible article placed therewithin. Further, such downward pulling is wasteful in that it may not separate only the lowermost flanged container from the nested stack. Of course, this waste unduly increases the cost of preparation and packaging of the comestible articles.
In view of the foregoing, it is advantageous to provide a container de-nesting apparatus able to separate the lowermost nested container from a stacked array thereof without generating a possibility of rupture to the receptacle portion or tearing of the flanges thereof. It is of further advantage to provide a container de-nesting apparatus that alternatively supports the flanges of the lowermost container in the array from the bottom thereof yet, as that support is moved away from the flanges of the lowermost container, the remaining containers in the array are lifted upwardly from the lowermost container to permit that lowermost container to fall, due to the influence of its own weight. It is also advantageous to associate a flanged container de-nesting apparatus with suitable automated conveyors, if desired, so that the separated containers may fall into the suitable conveyor apparatus. It is of even further advantage to provide a container de-nesting apparatus wherein a support surface on the support element is reciprocally movable so that movement in a first rectilinear direction separates the lowermost container and simultaneously lifts the remaining containers of the array therefrom, while movement in an opposite rectilinear direction places the now-lowermost container onto the support surface so that the separating operation may be repeated.